CORDIS - EU research results

Transport in strongly interacting nanosystems

Final Activity Report Summary - TSINANO (Transport in Strongly Interacting Nanosystems)

In spite of intense theoretical and experimental exploration over the past ten years, many features of one-dimensional systems (such as carbon nanotubes, fractional quantum Hall edge states, and quantum wires) are still not understood. Their physics is dominated by interactions, which lead to very strongly correlated states of matter deemed Luttinger liquids. Hence, one-dimensional systems are expected to exhibit very fascinating properties, such charge fractionalisation, spin charge separation and fractional statistics.

The main goal of the research is to theoretically understand and model quantities measurable in transport experiments, such as the conductance and the noise, as well as the local density of states measurable in an STM experiment. In particular, over the past two years the project has tried to understand how these quantities, in particular the high-frequency non-symmetrized noise, are affected by the interplay between the strong electronic interactions and the presence of metallic leads, Working close to the experiments, the project hoped that the analysis will allow one to prove charge fractionalisation in nanotubes, and retrieve information about spin-charge separation and fractional statistics.

Another direction of the research is graphene. Graphene has been studied extensively in the recent years, especially after it became possible to fabricate it through exfoliation. Its most fascinating aspect is the existence of the linearly-dispersing gapless excitations in the vicinity of the Dirac points. Moreover, new developments in the past years opened the perspective of large-scale production of graphene-based nano-devices. However, more theoretical issues need to be addressed, such as the effects of various substrates, the effects of disorder, and the possibility of opening a gap.

The project's main interest in graphene over the past two years consisted in analysing local measurements such as STM. For graphene, the STM measurements have till this point been used to extract information about the atomic structure, the number of layers, the linearity of the spectrum, the effects of the phonons, and about a gap opening. Very recent experiments showed that STM experiments can give access to other fundamental properties of graphene such as the chirality of its quasiparticles.